The present invention relates to an improvement of a bearing metal, particularly the bearing metal that is suitable for accepting a swinging motion such as a cross-head pin bearing for large marine diesel engines.
Conventionally, white metals have been used as bearing alloys for such cross-head pin bearings. As internal combustion engines, however, have became more and more powerful, white metals have revealed inherent defects: they have had an extremely short service life due to failure from fatigue. Because of this drawback, aluminum-tin bearing alloys containing up to, but not including, 45% by weight of tin having longer life than that of white metals have been used increasingly.
But when they have been used in a very poorly lubricated site such as a cross-head bearing and under dusty conditions, they also had a defect that they were poor in compatibility and embeddability. Therefore, a bearing alloy superior in compatibility and more capable of being embedded compared to said aluminum tin bearing alloys that contain up to, but not including, 45% by weight of tin has been strongly desired by industry, but such alloys have not yet been established in the market.
However, British Patent Specification No. 722552 discloses the alloy wherein the tin composition is 50% by weight. In consideration that the conventional high-tin aluminum bearing alloys are generally limited to those containing 20 to 40% by weight of tin, there is occasionally illustrated the case in the British patent specification wherein the tin composition is 50% by weight and which is rather exceptional.